Science has long known that ancient human ancestors used primitive tools millions of years ago – but in reality, we don't know how much these tools could have helped them survive. Portal arstechnica.com speak about an archaeological discovery that sheds light on the history of ancient tools.
Archaeologists from John Washington University have found stone tools preserved in 2.75 million year old sedimentary rocks in Kenya. They are a classic example of what archaeologists call Olduvian tools – meaning they were among the earliest sharp stone tools made by hominids. And those found in Kenya are also some of the oldest; only three other Olduvai sites in Africa date earlier.
Pieces of river rock chipped on one or both sides to give them a sharp edge were advanced technology 2.9 to 1.7 million years ago. Thus, they were used by some hominin species and at least many genera. The last hominins to use Olduvai tools were probably completely different from the first humans and led a completely different lifestyle. Over such a long period of time, the technology of stone tools changed less than the creatures that used it.
However, archaeologists typically see only short fragments of these fragments, one or two generations of hominids at each excavation site. Having so many layers of sedimentary rocks and artifacts preserved in Kenya is a rarity. Historical records, in the form of river sediments and volcanic tuff, record 300,000 years of Hominin craftsmanship, making similar types of tools using a refined skill set.
For context, this means that members of several ancient hominin species (possibly more than one) passed down their knowledge and experience for about 10,000 generations.
The archaeologists' discovery covers the transition period between the Pliocene and Pleistocene eras, during which Earth's climate became colder and drier. Pollen and other microscopic traces of plants in the sediment show that the coastal marsh once gradually dried up and transformed into a hot savanna dotted with shrubs. The hominins who lived there may have been exposed to forest fires and droughts, which changed the way the rivers functioned.
Sharp stone tools could help entire generations survive in a changing and drying world. During the warm and wet Pliocene, finding food would not have been difficult, but as conditions became harsher, hominins may have been forced to forage. On at least one animal bone, excavations have revealed notches indicating that ancient hominins butchered meat. In addition, these tools also allowed them to dig up plants with edible tubers and roots.
In short, research in Kenya may indicate that Olduvai technology may be even older than the first tools found by archaeologists. The earliest examples of tools found in Kenya are clearly the work of skilled artisans who understood where to strike the stone, at what angle, and how to shape the cutting edge. They also knew how to choose the right stone for their tools. In other words, these tools are clearly not the work of an ancient group of human ancestors who were just starting to break rocks with stone.
Today's wild chimpanzees can use round stone “hammers” to crack nuts and bones. In the process, they inevitably broke pieces of rock, so it's not difficult to imagine how an intelligent Australopithecus could have made a scientific discovery.
